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US 6,583,940 B2Granted
Projection system
AssigneeMinolta Co., Ltd.
InventorsJun Nishikawa, Shigeru Sawamura, Katsuhiro Takamoto
Life of this patent
Estimating the term…
Abstract
A projection system that is capable of providing a high-performance projection system and producing a high contrast projection image by using an optical modulation element, which can be positioned a predetermined distance away from an illumination optical system and a projection optical system. The optical modulation element is capable of modulating light received from the illumination optical system and projecting the modulated light to a projection optical system in the direction of a projection surface.
Claims27
A projection system, comprising:
- a light source;
- an illumination optical system for receiving light from said light source;
- an optical modulation element;
- a projection optical system;
- and
- a prism unit for reflecting light from said illumination optical system to said optical modulation element and for transmitting light from said optical modulation element to said projection optical system,
- wherein the following condition is satisfied:
- 100≦Xa≦250,
- where Xa (mm) represents a distance along an optical axis of the projection system from said optical modulation element to an exit pupil of said illumination optical system on an optical modulation element side of said illumination optical system.
6 more elements
A projection system, comprising:
- a light source;
- an optical modulation element;
- an illumination optical system defining an optical path from said light source to said optical modulation element;
- a projection optical system defining an optical path from said optical modulation element in a direction of a projection surface,
- wherein the following condition is satisfied
- 100≦Xa≦250,
- where Xa (mm) represents a distance along an optical axis of the projection system from said optical modulation element to an exit pupil of said illumination optical system on an optical modulation element side of said illumination optical system.
4 more elements
Dependencies are inferred from the claim text.